JPS5929605B2 - Method and device for continuously impregnating fiber bundles with resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method and method for continuously impregnating fiber bundles with resin under vacuum when molding reinforced plastics or producing prepreg as an intermediate material by the filament winding method. It is related to the device.

When a continuous fiber is impregnated with resin and wound around a mold to obtain a molded product of fiber-reinforced plastics, the resin is completely filled between the filaments in the fiber bundle.

It is well known that molded products with superior performance can be obtained by using fewer boards. Similarly, in prepreg as an intermediate material, if the filaments are completely filled with resin and the board content is small, the performance of the molded product obtained thereby can be improved. Conventionally, when continuously impregnating fibers with resin, the methods generally used were to pass the fibers through a resin bath under normal pressure, or to use rolls to impregnate the fibers with the resin attached to the bath. However, due to the air existing between the filaments of the fiber bundle, the resin does not penetrate sufficiently, and the product is wound up with air trapped in it, resulting in a high board content in the finished product, which makes it difficult to mold. This causes a decline in product performance. In order to reduce such boarding and improve adhesion between filaments, attempts have been made in the past to carry out the impregnation process under vacuum.

However, there are few methods for continuously impregnating fibers with resin under vacuum, and most of them use batch methods, which do not allow for in-line impregnation and winding into molds, making it impractical. poor.

Therefore, in order to continuously impregnate the fiber bundle with resin under vacuum, the method of inserting the fiber bundle into the resin bath and the method of drawing it out from the resin bath, that is, the method of vacuum sealing, becomes a problem. One method is to utilize differences in resin heads.

However, in order to increase the degree of vacuum, a head difference of approximately 10 m is required, which makes the impregnation equipment itself very large.Furthermore, the fiber bundle (roping) passes through this resin and then enters the vacuum chamber, so the filament The air in between becomes relatively difficult to escape. Similar to the above, there is a method that utilizes the head difference of mercury, but since it is necessary to pass through mercury, there is a risk that mercury will adhere to the fiber bundle, so this is not a very practical method.

The present invention solves the above problems and provides a method and apparatus that can effectively remove the air existing between the filaments of a fiber bundle and completely fill the spaces between the filaments with resin. .

Embodiments of the present invention will be described below based on the accompanying drawings.
FIG. 1 shows an example of a filament winding molding method using the apparatus of the present invention.

As shown in the figure, the fiber bundle A supplied from the supply 1 is
After passing through the resin bath 2, it is guided by a carriage part 3 and wound around a continuously rotating mold 4. FIG. 2 shows details of the resin bath 2, and the fiber bundle A supplied from the supply 1 is introduced into the bath 2 through the introduction passage 5.

The introduction passage 5 is one that can maintain a pressure difference between the inside of the tank 2 and the outside.

For example, as shown in Figure 3, a thin tube made of glass, metal, etc. is used, and in order to increase the degree of vacuum, the inner diameter is made as thin as possible compared to the apparent diameter of the fiber bundle, and the length of the tube is also a problem. Make it as long as possible. Alternatively, as shown in Figure 4, tank 2
Compressed air may be blown into the tube in the outer part to maintain the degree of vacuum using the ejector effect. Furthermore, as shown in FIG. 5, the fiber bundle A may be sandwiched from both sides by plate-like members made of, for example, Teflon resin and having smooth and elastic surfaces. Next, inside the tank 2,
Since the pressure is reduced from the vacuum port 6, the air present between the filaments of the fiber bundle A introduced into the tank is removed.

That is, since the air is removed before the fiber bundle is immersed in the resin bath, complete removal is achieved even under a relatively low degree of vacuum, unlike after resin impregnation. The fiber bundle A is immersed in the resin bath as guided by the rolls 7, and after the immersion is guided by the rolls 7, it heads toward the draw-out passage 8.

When the fiber bundle A passes through these rolls 7, if a suitable tension is applied, the resin penetrates into the inside of the fiber bundle due to the press-fitting action of the rolls and fills the gaps between the filaments. Next, the fiber bundle A is taken out into the atmosphere from the withdrawal passage 8.

This extraction passage 8 may be constructed of a thin tube similar to the introduction passage 5 (Fig. 3) or a stack of plate-like members (Fig. 5), but it may be constructed of a thin tube similar to that of the introduction passage 5 (Fig. It may also be a drawing die. When passing through the pull-out passage 8, the fiber bundle A has a resin attached to it, so it has a higher sealing performance than the introduction passage 5, and therefore, it has a relatively large inner diameter or a more flexible plate-like member (fifth (in the case of the figure) can be selected. However, by appropriately changing this inner diameter or flexibility, it is possible to adjust the amount of resin attached to the fiber bundle A, and
By further applying pressure from the outer periphery of the fiber bundle A, the air inside can be expelled and the resin can be press-fitted and permeated into the inside. The fiber bundle A that has come out into the atmosphere from the pull-out passage 8 has completely removed the air that existed between the filaments during resin impregnation, so the resin penetrates between the filaments due to external pressure (atmospheric pressure). However, the gap is sufficiently filled with resin.

FIG. 7 shows another embodiment of the invention.

As shown in the figure, a vacuum chamber 9 may be connected to the tank 2 so that the fiber bundle A can be directly supplied from the supply 1 in the vacuum chamber to the resin bath 2. In this case, the introduction passage 5 of the tank 2 does not need to be provided with a thin tube as described above, and therefore the degree of vacuum can be increased. In addition, it is preferable that the thin tube (FIG. 3) has at least a socket shaped like a wrapper tube.

Further, the inner diameter is not necessarily constant, and may be made to gradually become smaller toward the outlet. Incidentally, as shown in FIG. 2, it is preferable to provide a resin replenishing means 10 into the tank 2.

As described above, the present invention impregnates the fiber bundle with resin after completely removing the air in the fiber bundle in a vacuum chamber, and further penetrates the resin into the inside by the action of the rolls. The fiber bundle is controlled or press-fitted, and then taken out into the atmosphere and atmospheric pressure is used to fully fill the gaps in the fiber bundle with resin.The molded product obtained by the subsequent process has no board and has excellent performance. It will be excellent in terms of quality.

Moreover, these processes are carried out continuously,
It has high industrial applicability.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of the filament winding molding method using the apparatus of the present invention, Fig. 2 is an enlarged diagram of the main parts of the same,
Figures 3 and 4 are longitudinal sectional views of the fiber bundle passage;
6 is a longitudinal sectional view showing another modification of this passage, and FIG. 7 is a diagram showing another embodiment of the present invention. A... Fiber bundle, 1... Supply, 2.
...Resin bathtub, 4...Model, 5...
・Introduction passage, 8...Drawer passage, 9...
...Vacuum chamber.

Claims (1)

[Scope of Claims] 1. A fiber bundle is continuously introduced into a space inside a vacuum resin bath, and the fiber bundle is immersed in the resin bath while being guided by a roll. The resin is press-fitted when passing through the tube, and after the immersion is completed, the resin is passed through a pull-out passage where the seal is maintained by the fiber bundle to which the resin adheres.The passage allows the adjustment of the amount of resin adhesion and the press-fitting of the resin. A method for continuously impregnating fiber bundles with resin, which method comprises measuring the fiber bundles and then taking out the fiber bundles into the atmosphere outside the resin bath. 2. An airtight resin bathtub, an introduction passage for continuously introducing fiber bundles into the space inside the resin bathtub, a fiber bundle extraction passageway capable of maintaining a pressure difference between the inside and outside of the resin bathtub, and a fiber bundle introduction passageway for introducing the fiber bundles from the introduction passageway. The fiber bundle is made to pass through the resin bath from the space of the resin bath, and then taken out into the space again and further guided to the pull-out passage, and a means for vacuuming the inside of the resin bath. Continuous impregnation equipment.